Internalize some Docker types

Internalize the type declaration of a Docker image, so that we don't
need to pull in code when we just want to know how to parse out a JSON
object.  Carry a copy of the license that covered the sources from which
the definitions came.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

Closes: #75
Approved by: nalind

config.go

@@ -6,8 +6,8 @@ import (
 	"time"
 
 	"github.com/Sirupsen/logrus"
-	docker "github.com/docker/docker/image"
 	ociv1 "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/projectatomic/buildah/docker"
 )
 
 func copyDockerImageConfig(dimage *docker.Image) (ociv1.Image, error) {

docker/types.go

@@ -0,0 +1,92 @@
+package docker
+
+//
+//  Types extracted from Docker
+//
+
+import (
+	"time"
+
+	"github.com/docker/docker/api/types/container"
+	"github.com/opencontainers/go-digest"
+)
+
+// github.com/docker/docker/image/rootfs.go
+const TypeLayers = "layers"
+
+// github.com/docker/docker/image/rootfs.go
+// RootFS describes images root filesystem
+// This is currently a placeholder that only supports layers. In the future
+// this can be made into an interface that supports different implementations.
+type RootFS struct {
+	Type    string          `json:"type"`
+	DiffIDs []digest.Digest `json:"diff_ids,omitempty"`
+}
+
+// github.com/docker/docker/image/image.go
+// History stores build commands that were used to create an image
+type History struct {
+	// Created is the timestamp at which the image was created
+	Created time.Time `json:"created"`
+	// Author is the name of the author that was specified when committing the image
+	Author string `json:"author,omitempty"`
+	// CreatedBy keeps the Dockerfile command used while building the image
+	CreatedBy string `json:"created_by,omitempty"`
+	// Comment is the commit message that was set when committing the image
+	Comment string `json:"comment,omitempty"`
+	// EmptyLayer is set to true if this history item did not generate a
+	// layer. Otherwise, the history item is associated with the next
+	// layer in the RootFS section.
+	EmptyLayer bool `json:"empty_layer,omitempty"`
+}
+
+// github.com/docker/docker/image/image.go
+// ID is the content-addressable ID of an image.
+type ID digest.Digest
+
+// github.com/docker/docker/image/image.go
+// V1Image stores the V1 image configuration.
+type V1Image struct {
+	// ID is a unique 64 character identifier of the image
+	ID string `json:"id,omitempty"`
+	// Parent is the ID of the parent image
+	Parent string `json:"parent,omitempty"`
+	// Comment is the commit message that was set when committing the image
+	Comment string `json:"comment,omitempty"`
+	// Created is the timestamp at which the image was created
+	Created time.Time `json:"created"`
+	// Container is the id of the container used to commit
+	Container string `json:"container,omitempty"`
+	// ContainerConfig is the configuration of the container that is committed into the image
+	ContainerConfig container.Config `json:"container_config,omitempty"`
+	// DockerVersion specifies the version of Docker that was used to build the image
+	DockerVersion string `json:"docker_version,omitempty"`
+	// Author is the name of the author that was specified when committing the image
+	Author string `json:"author,omitempty"`
+	// Config is the configuration of the container received from the client
+	Config *container.Config `json:"config,omitempty"`
+	// Architecture is the hardware that the image is build and runs on
+	Architecture string `json:"architecture,omitempty"`
+	// OS is the operating system used to build and run the image
+	OS string `json:"os,omitempty"`
+	// Size is the total size of the image including all layers it is composed of
+	Size int64 `json:",omitempty"`
+}
+
+// github.com/docker/docker/image/image.go
+// Image stores the image configuration
+type Image struct {
+	V1Image
+	Parent     ID        `json:"parent,omitempty"`
+	RootFS     *RootFS   `json:"rootfs,omitempty"`
+	History    []History `json:"history,omitempty"`
+	OSVersion  string    `json:"os.version,omitempty"`
+	OSFeatures []string  `json:"os.features,omitempty"`
+
+	// rawJSON caches the immutable JSON associated with this image.
+	rawJSON []byte
+
+	// computedID is the ID computed from the hash of the image config.
+	// Not to be confused with the legacy V1 ID in V1Image.
+	computedID ID
+}